Signal processing device and signal processing method

Abstract

A signal processing device is provided that is capable of suppressing incongruity of color change in an image area while relieving fatigue of a user viewing content data to be displayed. The signal processing device includes a calculator, a setting unit, and a converter. The calculator sets a ratio to a display area of a first area in which a character is mainly displayed in the display area of the content data, and sets a ratio to the display area of a second area in which an object other than character such as an image is mainly displayed. The setting unit sets a target color temperature based on the ratio set by the calculator. The converter changes a current color temperature of the content data to the target color temperature set by the setting unit.

What is claimed is: 
     
         1 . A signal processing device comprising:
 a calculator that divides a display area of content data into a plurality of areas including a first area for mainly displaying a character and a second area for mainly displaying an object other than character, and calculates each of a first ratio of the first area to the display area and a second ratio of the second area to the display area;   a setting unit that sets a target color temperature of the content data based on the first ratio and the second ratio; and   a converter that changes a color temperature of the content data to the target color temperature.   
     
     
         2 . The signal processing device according to  claim 1 ,
 wherein the setting unit lowers the target color temperature as the first ratio becomes greater.   
     
     
         3 . The signal processing device according to  claim 1 ,
 wherein the calculator excludes from the first area, an area having chroma of a background color that is equal to or greater than a predetermined value in the first area.   
     
     
         4 . The signal processing device according to  claim 1 ,
 wherein the setting unit calculates a target color temperature of content data to be subsequently displayed, and then replaces a target color temperature of the content data currently being displayed with a color temperature between the target color temperature of the content data currently being displayed and the target color temperature of the content data to be subsequently displayed.   
     
     
         5 . The signal processing device according to  claim 1  further comprising a detector that detects a color temperature of ambient light,
 wherein the setting unit sets a color temperature between the color temperature detected by the detector and the color temperature set in accordance with the first ratio and the second ratio calculated by the calculator, as a target color temperature. 
 
     
     
         6 . A signal processing device comprising:
 a calculator that divides a display area of content data into a plurality of areas including a first area for mainly displaying a character and a second area for mainly displaying an object other than character, and calculates each of a first ratio of the first area to the display area and a second ratio of the second area to the display area; and   a converter that changes a current color temperature of the content data to a target color temperature,   wherein the target color temperature is a color temperature that depends on a ratio between the first area and the second area.   
     
     
         7 . A signal processing method comprising:
 dividing a display area of content data into a plurality of areas including a first area for mainly displaying a character and a second area for mainly displaying an object other than character;   calculating each of a first ratio of the first area to the display area and a second ratio of the second area to the display area;   setting a target color temperature of the content data based on the first ratio and the second ratio; and   changing a present color temperature of the content data eventually to the set target color temperature.